Chester, 44, killed Ryman while on a six-month crime spree where he murdered four other people, according to the Associated Press.

"You should know who killed your loved one," Chester said before his execution. "Don't hate me. I'm sorry for taking your loved one. Elroy Chester wasn't a bad man. I don't care what anybody says. A lot of people say I didn't commit those murders. I really did it."

The AP reported that DNA evidence would later connect Chester to the rapes and ballistics tests of a gun in Chester's possession to the murder. Authorities said the weapon was taken in one of Chester's 25 Port Arthur burglaries.

"After 15 years, it's a long time coming," Barry Ryman, brother of the slain firefighter, told the Associated Press after Chester's death. Willie Ryman was a member of the Port Arthur Fire Department. "It's not complete closure. Our brother's still not here. The other victims are not here."

Earlier Wednesday, the U.S. Fifth Circuit Court of Appeals denied a stay of execution request, said the Houston Chronicle. The newspaper said a new panel was assigned the case Tuesday after Chester's attorneys requested a new review of the execution without federal judge Edith Jones.

The Chronicle said Chester's attorney had filed a misconduct complaint against Jones, saying she commented on his client's case during a speech in February.

The Houston Chronicle reported that U.S. Supreme Court Justice John Roberts formally ordered a review of the complaint against Jones Wednesday. Roberts assigned the Judicial Council of the District of Columbia Circuit to review hear the complaint, the Chronicle said.

Chester became the seventh convicted killer executed this year in Texas and the 499th since the state resumed carrying out capital punishment in 1982 following a nearly two-decade-long hiatus, said the Associated Press.